<?php

    /**
     * PHPExcel_CachedObjectStorage_Memory
     * Copyright (c) 2006 - 2015 PHPExcel
     * This library is free software; you can redistribute it and/or
     * modify it under the terms of the GNU Lesser General Public
     * License as published by the Free Software Foundation; either
     * version 2.1 of the License, or (at your option) any later version.
     * This library is distributed in the hope that it will be useful,
     * but WITHOUT ANY WARRANTY; without even the implied warranty of
     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
     * Lesser General Public License for more details.
     * You should have received a copy of the GNU Lesser General Public
     * License along with this library; if not, write to the Free Software
     * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
     * @category   PHPExcel
     * @package    PHPExcel_CachedObjectStorage
     * @copyright  Copyright (c) 2006 - 2015 PHPExcel (http://www.codeplex.com/PHPExcel)
     * @license    http://www.gnu.org/licenses/old-licenses/lgpl-2.1.txt    LGPL
     * @version    ##VERSION##, ##DATE##
     */
    class PHPExcel_CachedObjectStorage_Memory extends PHPExcel_CachedObjectStorage_CacheBase implements PHPExcel_CachedObjectStorage_ICache {
        /**
         * Add or Update a cell in cache identified by coordinate address
         * @param    string        $pCoord Coordinate address of the cell to update
         * @param    PHPExcel_Cell $cell   Cell to update
         * @return    PHPExcel_Cell
         * @throws    PHPExcel_Exception
         */
        public function addCacheData($pCoord, PHPExcel_Cell $cell) {
            $this->cellCache[$pCoord] = $cell;
            //    Set current entry to the new/updated entry
            $this->currentObjectID = $pCoord;
            return $cell;
        }

        /**
         * Get cell at a specific coordinate
         * @param     string $pCoord Coordinate of the cell
         * @throws     PHPExcel_Exception
         * @return     PHPExcel_Cell     Cell that was found, or null if not found
         */
        public function getCacheData($pCoord) {
            //    Check if the entry that has been requested actually exists
            if (!isset($this->cellCache[$pCoord])) {
                $this->currentObjectID = null;
                //    Return null if requested entry doesn't exist in cache
                return null;
            }
            //    Set current entry to the requested entry
            $this->currentObjectID = $pCoord;
            //    Return requested entry
            return $this->cellCache[$pCoord];
        }

        /**
         * Clone the cell collection
         * @param    PHPExcel_Worksheet $parent The new worksheet
         */
        public function copyCellCollection(PHPExcel_Worksheet $parent) {
            parent::copyCellCollection($parent);
            $newCollection = [];
            foreach ($this->cellCache as $k => &$cell) {
                $newCollection[$k] = clone $cell;
                $newCollection[$k]->attach($this);
            }
            $this->cellCache = $newCollection;
        }

        /**
         * Clear the cell collection and disconnect from our parent
         */
        public function unsetWorksheetCells() {
            // Because cells are all stored as intact objects in memory, we need to detach each one from the parent
            foreach ($this->cellCache as $k => &$cell) {
                $cell->detach();
                $this->cellCache[$k] = null;
            }
            unset($cell);
            $this->cellCache = [];
            //    detach ourself from the worksheet, so that it can then delete this object successfully
            $this->parent = null;
        }

        /**
         * Dummy method callable from CacheBase, but unused by Memory cache
         * @return    void
         */
        protected function storeData() {
        }
    }
